Reappraisal of Morphological Differences between Renal Medullary Carcinoma, Collecting Duct Carcinoma, and Fumarate Hydratase-Deficient Renal Cell Carcinoma

Renal medullary carcinomas (RMCs) and collecting duct carcinomas (CDCs) are rare subsets of lethal high-stage, high-grade distal nephron-related adenocarcinomas with a predilection for the renal medullary region. Recent findings have established an emerging group of fumarate hydratase (FH)-deficient tumors related to hereditary leiomyomatosis and renal cell carcinoma (HLRCC-RCCs) syndrome within this morphologic spectrum. Recently developed, reliable ancillary testing has enabled consistent separation between these tumor types. Here, we present the clinicopathologic features and differences in the morphologic patterns between RMC, CDC, and FH-deficient RCC in consequence of these recent developments. This study included a total of 100 cases classified using contemporary criteria and ancillary tests. Thirty-three RMCs (SMARCB1/INI1-deficient, hemoglobinopathy), 38 CDCs (SMARCB1/INI1-retained), and 29 RCCs defined by the FH-deficient phenotype (FH/2SC or FH/2SC with FH mutation, regardless of HLRCC syndromic stigmata/history) were selected. The spectrum of morphologic patterns was critically evaluated, and the differences between the morphologic patterns present in the 3 groups were analyzed statistically. Twenty-five percent of cases initially diagnosed as CDC were reclassified as FH-deficient RCC on the basis of our contemporary diagnostic approach. Among the different overlapping morphologic patterns, sieve-like/cribriform and reticular/yolk sac tumor-like patterns favored RMCs, whereas intracystic papillary and tubulocystic patterns favored FH-deficient RCC. The tubulopapillary pattern favored both CDCs and FH-deficient RCCs, and the multinodular infiltrating papillary pattern favored CDCs. Infiltrating glandular and solid sheets/cords/nested patterns were not statistically different among the 3 groups. Viral inclusion-like macronucleoli, considered as a hallmark of HLRCC-RCCs, were observed significantly more frequently in FH-deficient RCCs. Despite the overlapping morphology found among these clinically aggressive infiltrating high-grade adenocarcinomas of the kidney, reproducible differences in morphology emerged between these categories after rigorous characterization. Finally, we recommend that definitive diagnosis of CDC should only be made if RMC and FH-deficient RCC are excluded

Upper Gastrointestinal Bleeding from Gastric Amyloidosis in a Patient with Smoldering Multiple Myeloma

Amyloidosis is a common complication of patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM). This proteinaceous material can be deposited intercellularly in any organ system, including the gastrointestinal (GI) tract. In the GI tract, amyloidosis affects the duodenum most commonly, followed by the stomach and colorectum. Gastric amyloidosis causes symptoms of nausea, vomiting, early satiety, abdominal pain, and GI bleeding. A case of upper GI bleeding from gastric amyloidosis is presented in a patient with SMM. Esophagogastroduodenoscopy (EGD) revealed a gastric mass. Endoscopic biopsies revealed amyloid deposition in the lamina propria, consistent with gastric amyloidosis. Liquid chromatography tandem mass spectrometry performed on peptides extracted from Congo red-positive microdissected areas of paraffin-embedded stomach specimens revealed a peptide profile consistent with AL- (lambda-) type amyloidosis. Based on this and multiple other case reports, we recommend that patients with GI bleeding and MGUS, SMM, or MM undergo EGD and pathologic examination of endoscopic biopsies of identified lesions using Congo red stains for amyloidosis for early diagnosis and treatment

Machine learning methods to predict mechanical ventilation and mortality in patients with COVID-19.

BackgroundThe Coronavirus disease 2019 (COVID-19) pandemic has affected millions of people across the globe. It is associated with a high mortality rate and has created a global crisis by straining medical resources worldwide.ObjectivesTo develop and validate machine-learning models for prediction of mechanical ventilation (MV) for patients presenting to emergency room and for prediction of in-hospital mortality once a patient is admitted.MethodsTwo cohorts were used for the two different aims. 1980 COVID-19 patients were enrolled for the aim of prediction ofMV. 1036 patients' data, including demographics, past smoking and drinking history, past medical history and vital signs at emergency room (ER), laboratory values, and treatments were collected for training and 674 patients were enrolled for validation using XGBoost algorithm. For the second aim to predict in-hospital mortality, 3491 hospitalized patients via ER were enrolled. CatBoost, a new gradient-boosting algorithm was applied for training and validation of the cohort.ResultsOlder age, higher temperature, increased respiratory rate (RR) and a lower oxygen saturation (SpO2) from the first set of vital signs were associated with an increased risk of MV amongst the 1980 patients in the ER. The model had a high accuracy of 86.2% and a negative predictive value (NPV) of 87.8%. While, patients who required MV, had a higher RR, Body mass index (BMI) and longer length of stay in the hospital were the major features associated with in-hospital mortality. The second model had a high accuracy of 80% with NPV of 81.6%.ConclusionMachine learning models using XGBoost and catBoost algorithms can predict need for mechanical ventilation and mortality with a very high accuracy in COVID-19 patients

Early, Isolated Duodenal Mucosa-Associated Lymphoid Tissue Lymphoma Presenting without Symptoms or Grossly Apparent Endoscopic Lesions and Diagnosed by Random Duodenal Biopsies

Clinical data regarding mucosa-associated lymphoid tissue lymphoma (MALToma) solely involving the duodenum are sparse because of the relative rarity of the disease. A comprehensive literature review revealed only 17 cases reported until 2004, and only a moderate number of cases have been reported since. MALToma can be asymptomatic in its very early stages but frequently produces localized or nonspecific symptoms, including early satiety, abdominal pain, vomiting, and involuntary weight loss in later stages. While gastric MALToma is strongly associated with gastric Helicobactor pylori infection, duodenal MALToma is often unassociated with H. pylori infection. A 74-year-old female presented with only dysphagia (without symptoms referable to a duodenal lesion), without systemic ‘B’ symptoms, and with no evident duodenal lesions at esophagogastroduodenoscopy; however, she was diagnosed with duodenal MALToma by pathologic examination of random duodenal biopsies performed to exclude celiac disease. An important clinical feature of this case is that duodenal MALToma was diagnosed by pathologic analysis of duodenal biopsies despite (1) no endoscopically apparent duodenal lesions; (2) duodenal involvement without gastric involvement; (3) lack of symptoms attributable to duodenal MALToma, and (4) absence of evident H. pylori infection. This work shows that early duodenal MALToma can be difficult to diagnose because of absent symptoms, absence of gastric involvement, absence of endoscopic abnormalities, and absence of H. pylori infection; it may require random duodenal biopsies for diagnosis

Bilateral Testicular Infarction from IgA Vasculitis of the Spermatic Cords

A 51-year-old man with type 2 diabetes mellitus and chronic obstructive pulmonary disease presented to the emergency room with increasing bilateral leg pain, rash, and scrotal swelling with pain. Skin biopsy from his thigh revealed IgA-associated vasculitis. Due to hematuria, a renal biopsy was performed and showed an IgA glomerulonephritis with focal fibrinoid necrosis and neutrophil accumulation. Bilateral orchiectomies were performed in two separate procedures ten and thirteen days after the renal biopsy, as a result of uncontrolled abscess formation in testicles. Microscopically, both testicles revealed large abscess formation destroying almost the entire testicular parenchyma without tumor cells. Spermatic cord margins were further scrutinized microscopically to show bilateral vasculitis in many small size vessels, confirmed by positive endothelial staining for IgA. Some of the affected arteries revealed central organizing thrombi with recanalization features, highly suggestive of vasculitis-associated thrombi formation, resulting in testicular ischemic infarction and abscess formation. We conclude that this adult patient developed a severe form of Henoch-Schönlein purpura, with vasculitis affecting multiple organs, including the most serious and unusual complication of bilateral testicular infarction

Tubulocystic Carcinoma of the Kidney With Poorly Differentiated Foci: A Frequent Morphologic Pattern of Fumarate Hydratase-deficient Renal Cell Carcinoma

An emerging group of high-grade renal cell carcinomas (RCCs), particularly carcinomas arising in the hereditary leiomyomatosis renal cell carcinoma syndrome (HLRCC), show fumarate hydratase (FH) gene mutation and loss of function. On the basis of similar cytomorphology and clinicopathologic features between these tumors and cases described as tubulocystic carcinomas with poorly differentiated foci (TC-PD) of infiltrative adenocarcinoma, we hypothesized a relationship between these entities. First, 29 RCCs with morphology of TC-PD were identified retrospectively and assessed for FH expression and aberrant succination (2SC) by immunohistochemistry (IHC), with targeted next-generation sequencing of 409 genes-including FH-performed on a subset. The 29 TC-PD RCCs included 21 males and 8 females, aged 16 to 86 years (median, 46), with tumors measuring 3 to 21 cm (median, 9) arising in the right (n=16) and left (n=13) kidneys. Family history or stigmata of HLRCC were identifiable only retrospectively in 3 (12%). These tumors were aggressive, with 79% showing perinephric extension, nodal involvement in 41%, and metastasis in 86%. Of these, 16 (55%) demonstrated loss of FH by IHC (14/14 with positive 2SC). In contrast, 5 (17%) showed a wild-type immunoprofile of FH+/2SC-. An intriguing group of 8 (28%) showed variable FH± positivity, but with strong/diffuse 2SC+. Next-generation sequencing revealed 8 cases with FH mutations, including 5 FH-/2SC+ and 3 FH±/2SC+ cases, but none in FH+/2SC- cases. Secondly, we retrospectively reviewed the morphology of 2 well-characterized cohorts of RCCs with FH-deficiency determined by IHC or sequencing (n=23 and n=9), unselected for TC-PD pattern, identifying the TC-PD morphology in 10 (31%). We conclude that RCCs with TC-PD morphology are enriched for FH deficiency, and we recommend additional workup, including referral to genetic counseling, for prospective cases. In addition, based on these and other observations, we propose the term FH-deficient RCC as a provisional term for tumors with a combination of suggestive morphology and immunophenotype but where genetic confirmation is unavailable upon diagnosis. This term will serve as a provisional nomenclature that will enable triage of individual cases for genetic counseling and testing, while designating these cases for prospective studies of their relationship to HLRCC

Clinicopathologic features and prognostic impact of lymph node involvement in patients with breast implant-associated anaplastic large cell lymphoma

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a rare T-cell lymphoma that arises around breast implants. Most patients manifest with periprosthetic effusion, whereas a subset of patients develops a tumor mass or lymph node involvement (LNI). The aim of this study is to describe the pathologic features of lymph nodes from patients with BI-ALCL and assess the prognostic impact of LNI. Clinical findings and histopathologic features of lymph nodes were assessed in 70 patients with BI-ALCL. LNI was defined by the histologic demonstration of ALCL in lymph nodes. Fourteen (20%) patients with BI-ALCL had LNI, all lymph nodes involved were regional, the most frequent were axillary (93%). The pattern of involvement was sinusoidal in 13 (92.9%) cases, often associated with perifollicular, interfollicular, and diffuse patterns. Two cases had Hodgkin-like patterns. The 5-year overall survival was 75% for patients with LNI and 97.9% for patients without LNI at presentation (P=0.003). Six of 49 (12.2%) of patients with tumor confined by the capsule had LNI, compared with LNI in 8/21 (38%) patients with tumor beyond the capsule. Most patients with LNI achieved complete remission after various therapeutic approaches. Two of 14 (14.3%) patients with LNI died of disease compared with 0/56 (0%) patients without LNI. Twenty percent of patients with BI-ALCL had LNI by lymphoma, most often in a sinusoidal pattern. We conclude that BI-ALCL beyond capsule is associated with a higher risk of LNI. Involvement of lymph nodes was associated with decreased overall survival. Misdiagnosis as Hodgkin lymphoma is a pitfall